Balanced valve.



PATBNTBD MAR. 1'7, 190s.

z SHEETS-SHEET 1,

S. MARTIN. BALANGED VALVE.

APPLIUATION Hmm 00T. 1s. 1902,

gli n NO MODEL.

.AJ I A No. 722,733; PATBNTED MAR. 17, 1909.

' s. MARTIN.

BALANGED VALVE.

APPLIOATION FILED 007213, 1902. No MODEL f 2 SHEETS-SHEET 2.

,tional view on the line X X of Fig. S.

UNITED raras ATENT rFiCE.

SAMUEL MARTIN, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR OF ONE- I-IALF TOWILLIAM T. JONES AND A. B. MOVAY, OF PITTSBURG,

PENNSYLVANIA BALANCED VALVE.

SPECIFICATION forming part of Letters Patent N o, 722,733, dated March17, 1903. Application filed October 13, 1902. Serial No. 127,110.V (Nomodel.)

T0 all whom it may concern.-

Be it known that I, SAMUEL MARTIN, a citizen of the United States,residing at Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements inBalanced Valves, of which the following is a specification, referencebeing had therein to the accompanying drawings, forming part of thisspecification, in which- Figure 1 is a partial longitudinal sectionalview of an engine-cylinder provided with my improved balanced valve.Fig. 2 is a similar view showing the valve shifted to one side andregistering with the inlet and exhaust ports, respectively. Fig. 3 is ahorizontal sectional view of the valve-chest on the line III III of Fig.l, the valve being shown in plan view partially broken away. Fig. 4 is across-sectional view on the line IV IV of Fig. l. Fig. 5 is across-sectional view on the line V V of Fig. 3. Fig. 6 is a perspectiveview of the valve detached. Fig. 7 is a view similar to Fig. 1, showinga modified construction of valve. Fig. S is asimilar view showing thevalve shifted. Fig. 9 is a horizontal sectional view similar to Fig. 3.Fig. l0 is a cross-sec- Fig. 1l is a detached perspective view of thevalve.

My invention refers to the class of balanced valves wherein means areprovided for relieving or counter-acting the frictionidue tosteampressure and tending to hold the valve to its seat. It is wellunderstood that such pressure renders the operation of valves,especially with large sizes, very difiicult, and my invention isdesigned to overcome such difficulty, aswell as to contribute to thegeneral efciency of the valve.

My improvement consists in the construction of the valve itself, wherebya measured quantity of steam is supplied to the port at each operation;to the delivery-port thereto; the circulation-port for providing acounterpressure; the regulating-valve for governing the supply, andother details of construction,

which shall be more fully hereinafter set forth. Referring now to thedrawings, 2 is the usual cylinder, provided with inlet-ports 3 3valve-rod 7 and suitable eccentric or other 1 gearing.v Valveclearance-space is provided at each end of the valve, which space isalso utilized in the open-ended construction of Sheet 2 for circulationto the engine-ports. The interior of valve 6 is hollow, and it may beclosed by a surrounding wall and provided on its under face with ports 8and exhaustport 9, adapted to establish communication with ports 3 and 4of the cylinder, as on Sheet 1, or it may he provided with end openings21, through which the steam escapes to the interior of the valve-chamberat each end and thence to the ports 3 when uncovered, as on Sheet 2.

At one end the valve is provided with an inlet-port 10, adapted toregister in the middle position of the valve, as in Figs. 1 and 7, withan inlet supply-port 11 in the end wall of the valve-chamber, to whichthe steam is supplied by any suitable connection. In the upper portionof the valve is a transverse port 12 of suiiicient width to alwaysregister with supply-port 11 in all positions of the valve, the purposeof which port is to supply steam-pressure against the other end ot thevalve, thus equalizing the pressure against the closed portion of theinlet end. For the purpose of confining the steam at such other end tothe area of the valve 6 alone and preventing it from escaping to theinterior I employ a pressure-plate 13, recessed at 14 on the interiorfor a portion equivalent to the counteracting pressure area desired andhaving a surrounding bearing-surface adapted to make a tight fit againstthe end of the valve. Temper-screws 15 bear against cushion-springs 16,which in turn bear against the plate, so that the plate may bedelicately adjusted against the valve without unnecessary rigidity.

Mounted in a suitable bearing 17 in the valve-chest is a throttle-valve18, provided with a port 19, adapted to register with inletport 11 andwith the supply-opening 2O and by which the volume of steam admitted tothe valve-chest inlet-port may be accurately regulated according to theload. Ihave found considerable advantage in thus locating thethrottling-valve and incorporating it with the valve-chest, resulting ingreat compactness of construction and convenience of manipulation.

In operation a charge of steam is admitted to the hollow valve at itsmiddle position, the ports 10 and 1l being in register and both ports 3being closed, as in Fig. l. Movement of the valve toward either end willclose ports 10 l1 and uncover one of ports 3, placing it either inregister with the closed interior through one of the ports 8 or with theinterior of the valve-chamber through open end 21, Fig. 8, into whichthe charge of steam under pressure has been delivered and from which itwill then pass through one of ports 3 to one end of the cylinder beforea new charge is again admitted. By this construction and operation itwillA be seen that upon the escape of steam through ports 3 pressureupon any of the exterior-,surfaces of valve 6 will be relieved and anybinding or frictional pressure will be reduced to a minimum, furthersupply of steam being out olf until port 10 of the valve is again inregister with port ll. In the closed construction of valve there is noescape of steam to the surrounding interior of the valve-chamber and nocommunication except through ports 8 or ends 2l to ports 3, while inboth constructions the charge of steam is cut o from the main supply andno more steam admitted until such charge is delivered to the cylinder.

The construction is very simple and not liable to get out of order,while the advantages of the invention will be appreciated by all thosefamiliar with this class of mechanism and the ease of operation of thevalve is greatly increased.

Having described my invention, what I claim is 1. A slide-valve having ahollow interior and an inlet-port adapted to register with a supply-portat the middle position of the valve only, substantially as set forth. 2.A slide-valve having a hollow interior and an inlet-port adapted toregister with a supply-port and a transverse pressure-supply port,extending laterally atv each side beyond the inlet-port, substantiallyas set forth.

3. A slide-valve having a hollow interior and an inlet-port adapted toregister with a supply-port at the middle position of the valve only,and delivery-ports adapted to register with the inlet-ports of acylinder, substantially as set forth.

4:. The combination with avalve-chest provided with an inlet-port, of ahollow valve provided with a port adapted to register therewith at itsmiddle position, and to out '0E the supply therefrom upon movement ineither direction, substantially as set forth.

5. The combination with a valve-chest provided with an inlet-port andacontrollingvalve, of a hollow valve provided with aport adapted toregister therewith at its middle position, and to cut off the supplytherefrom upon movement in either direction, substantially as set forth.

6. The combination with a valve-chest provided with an inlet-port, of ahollow valve provided with a port adapted to register therewith at itsmiddle position, and provided with ports adapted to register withcylinder-ports, substantially as set forth.

7. The combination with a valve-chest provided with an inlet-port, and apressure-plate at the opposite side, of a hollow valve provided with asupply-port, and a separate pressure-port, adapted to register with theinlet-port, substantially as set forth.

8. The combination with a valve-chest provided with an inlet-port, and apressure-plate at the opposite side, of a hollow valve provided with asupply-port, adapted to register therewith at the middle position of thevalve only, and a separate pressure-port adapted to register with saidinlet-port at all positions of the valve, substantially as set forth.

9. The combination with a steam-cylinder and a valve-chest providedvwith an inlet-port and ports leading to each end of the cylinderrespectively, of a hollow valve having inclosing walls, a port adaptedto register with the inlet-port, and ports adapted to register with thecylinder-ports respectively, substantially as set forth.

10. The combination with a steam-cylinder and a valve-chest providedwith an inlet-port JAS. J. MCAFEE, C. M. CLARKE.

IIO

